Vapor Pressure

Definition - What does Vapor Pressure mean?

Vapor pressure is the pressure that is exerted by a vapor at a certain given temperature in a closed system when the entire system is operating in a thermodynamic equilibrium. Vapor pressure indicates a liquid’s evaporation rate. The molecules in a liquid or a solid material have a tendency to transit from one phase to other phase under high vapor pressure.

Vapor pressure may also be known as equilibrium vapor pressure.

Corrosionpedia explains Vapor Pressure

The vapor pressure of a liquid is dependent on the temperature of the liquid, such that as the temperature of the liquid increases, its vapor pressure also increases. Similarly, as the temperature decreases, its vapor pressure also decreases. When the temperature is high enough, the material usually changes to its gaseous form because the molecules of the material absorb enough heat energy to make them escape from the liquid phase to the gaseous phase.